Lens astigmatism?

I'm seeking advice on a lens problem.

I recently bought Reikan Focal to tune my lenses.   On a Nikon D500 and Nikon 600mm F/4 G (bough used but pristine a year ago) Focal reports serious astigmatism.  Should I take this seriously and have the lens repaired?   Or is there another way (other tests) to assess this problem?

Bob

Hi Bob:  I don't know much about it myself, but here's a link to what looks like a good discussion.
http://www.dearsusan.net/mastering-lens-testing-astigmatism-and-field-curvature/

 

Dennis thanks for the useful pointer.  I'm now trying to get some idea about the validity of the Reikan Focal analysis.  It tells me that my lens exhibits unusual astigmatism.  I don't see it in test shots, but maybe I simply don't know what to look for.   I might take the Focal results on their face but there is some information that their software on Nikon/Mac has some problems, so I am uncertain.  I have contacted Reikan, but I wondered if experts on this forum might have some insight into this software.

Aside from the Reikan analysis, I'd like to understand how to assess astigmatism by looking at test photos.

Thanks again,

 Bob

"I'm now trying to get some idea about the validity of the Reikan Focal analysis.  It tells me that my lens exhibits unusual astigmatism.  I don't see it in test shots, but maybe I simply don't know what to look for."

There is no perfect lens, there is no perfect processing program, there is no perfect image viewing technology. We do the best we can with many factors of limitation.

Things like the Reikan app can be very useful, but the takeaway for me on issues like this is, if you view the images at 100% on your monitor and don't see a problem of any consequence, then don't worry about it. Much more important than any possible or perceived esoteric technical flaw is how well does the image communicate to your viewers what you want them to see and experience. 

- Greg
 

+1 for Greg's response. My thoughts exactly.

Greg, Alberto,

Thanks that is exactly the kind of advice I was looking for.  

By the way, Reikan was responsive, explaining that testing for astigmatism in long lenses is complicated (motion, lighting, target, etc.), how to control the test environment to minimize complications,  and that they can review my test results.  

Bob